In conventional liquid crystal displays, when liquid crystal molecules in the dark state are arranged perpendicular to a light source, the birefringence property of the liquid crystal molecules may enable light of a relatively large incident angle to pass through and to be emitted out of a screen. Consequently, light leakage at large viewing angles is observed in the displays.
With respect to the foregoing problem, the prior art provides a technical solution, in which an optical film layer having an optical lens structure is disposed on a light-emitting surface of a liquid crystal layer. The optical lens structure has a refractive index lower than that of the optical film layer such that the light emitting angle of incident light can be increased, thereby diverging incident light beams. However, the optical lens in the foregoing technical solution has disadvantages. For example, when light is incident into a side edge of the optical lens at a relatively large incident angle, the light will be totally reflected off the side surface of the lens structure when the incident angle exceeds a critical value since the light is incident from a medium of higher refractive index to that of a lower refractive index, and the reflected light will be emitted out of the display along a front view direction of the display. Consequently, the contrast ratio of the display along the front view direction is reduced.